(Reuters) - Varo Energy BV’s owners, U.S. private equity firm Carlyle Group (CG.O) and commodities trader Vitol, are looking at an initial public offering next year that could value the European oil refiner at about $2 billion, the Wall Street Journal reported on Wednesday.

Varo is expected to list its shares on the Amsterdam stock exchange, the Journal reported, citing people familiar with the matter.

Vivo Energy Investments BV, a fuel-stations operator partially backed by Vitol, is also gearing up for a possible IPO next year that could value the company at above $3 billion, the newspaper said.

A spokeswoman for Varo Energy said the company does not “comment on industry speculation,” while a Vitol representative declined to comment.

Carlyle was not immediately available for comment outside regular business hours.